Multi-station machine for automatic performance of sequential operations

ABSTRACT

In preferred form, a cylinder head casting defining machine having a plurality of work stations through which the cylinder head castings are moved on guide rails by a crank operated harmonic transfer mechanism which combines fast transfer from station to station with slow initial and terminal portions of the movement so that excessive shocks and part overrun are avoided. A pneumatic tool actuating mechanism is mechanically interconnected with the transfer means to positively time operation of the definning tools to occur during the return stroke of the transfer mechanism.

United States Patent Dirks [4 1 June 20, 1972 [54] MULTI-STATION MACHINEFOR AUTOMATIC PERFORMANCE OF SEQUENTIAL OPERATIONS [72] Inventor:Chauncey L. Dirks, Rochester, Mich.

[73] Assignee: General Motors Corporation, Detroit,

'Mich.

[22] Filed: June 26, 1970 [21] Appl. No.: 50,167

[52] US. Cl ..29/563, 29/33 P, 198/221 [51] Int. Cl ..B23q 7/04, 865g25/08 [58] Field of Search ..29/33 A, 33 P, 563, 33 R; 90/21 R, 21 A,83; 408/70 [56] References Cited UNITED STATES PATENTS 2,583,968 1/1952Rosseau ..198/221X 1,437,410 12/1922 Evans et Primary Examiner-GilWeidenfeld Attomey-J. L. Carpenter and Robert J. Outland [57] ABSTRACTIn preferred form, a cylinder head casting defining machine having aplurality of work stations through which the cylinder head castings aremoved on guide rails by a crank operated harmonic transfer mechanismwhich combines fast transfer from station to station with slow initialand terminal portions of the movement so that excessive shocks and panoverrun are avoided, A pneumatic tool actuating mechanism ismechanically interconnected with the transfer means to positively timeoperation of the definning tools to occur during the return stroke ofthe transfer mechanism.

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I saw 5 or 5 FLT. REG LU tt 1 VALVE SEAT DE-FIN CYLINDER 4=I= 2 VALVESEAT DE-FIN CYLINDER WATER HOLE DE-FIN CYLINDER OIL RETURN HOLE DE-FINCYLINDER INTAKE 8. END DE-FIN CYLINDER EXHAUST PORT DE-FIN CYLIN DERIN'VENTOR.

gaz mce y I. 862145 ATTORNEY MULTI-STATION MACHINE FOR AUTOMATICPERFORMANCE OF SEQUENTIAL OPERATIONS BACKGROUND OF THE INVENTION Thisinvention relates to multi-station machines for automatically performinga series of sequential operations on a plurality of individual partsand, in its more particular aspects, to machines for removing fins fromcastings, such as cylinder head castings.

In the art relating to multi-station machines for performing a series ofmechanical operations on individual parts, it is known to provideautomatic intermittent transfer mechanisms for moving the parts fromstation to station. Such mechanisms often include quite elaboratecontrol arrangements to permit the transfer of the parts to take placeonly when the operations on the parts at the various stations have beencompleted. When high transfer speeds are involved, intermittent transfermechanisms often require special stop devices to prevent the individualparts from riding past their intended station locations. Satisfying allthe requirements of high speed transfer mechanisms with interconnectedtool control has, in general, required relatively complex mechanisms.

SUMMARY OF THE INVENTION The present invention provides a multi-stationmachine in which a simple crank type drive is used to provide a harmonicmotion for an intermittent transfer mechanism which operates at hightransfer speeds but does not require special stopping devices for theparts at the various stations. In addition, mechanical interconnectionof the crank mechanism with the operating tool controls provides for allmachine operations to take place on the return stroke of the transfermechanism so that a simple continuously operating drive may be utilized.

In specific form, the machine includes guide rails traversing aplurality of work stations and arranged to carry individual cylinderhead castings from which casting fins are removed by special toolsprovided at the various work stations. A longitudinal transfer bar andsimple gravity latches which advance the castings on the forward strokeand ride over the castings on the return stroke are utilized as maincomponents of the transfer mechanism.

These and other advantages of the invention may be more fully understoodfrom the following description of a preferred embodiment, taken togetherwith the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. I is a front elevational view of a multi-station cylinder headdefining machine having transfer and tool means according to theinvention and showing exemplary portions thereof;

FIG. 2 is a plan view showing the transfer mechanism drive portions ofthe machine of FIG. 1 as viewed in the direction of the arrows 22;

FIG. 3 is an enlarged elevational view showing details of the drive andtransfer mechanism of the machine of FIG. 1; 7

FIG. 4 is a pictorial view illustrating a cylinder head casting of thetype from which casting fins are to be removed by the machine of FIG. 1;

FIG. 5 is a cross-sectional view taken in the plane indicated by theline 5-5 of FIG. 1 and showing details of one of the casting definningwork stations;

FIG. 6 is a cross'sectional view taken in the plane indicated by theline 6-6 of FIG. I and showing details of another of the castingdefinning work stations; and

FIG. 7 is a schematic diagram of the pneumatic control and toolactuating system for the machine of FIG. 1 showing its mechanicalinterconnection with the transfer drive mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings indetail, numeral 10 generally indicates a multi-station cylinder headcasting definning machine formed according to the invention. Machine 10includes a fabricated steel frame 12 on which is carried a pair ofbuilt-up steel guide rails 14 which extend parallel to one another theentire length of the frame 12 and provide both guide and support meanson which a plurality of cylinder head castings 16 may be carried andmoved from station to station through the machine.

Frame 12 is provided with a plurality of vertically extending legs 18which support the frame and guide rails 14 and divide the frame into aplurality of equally spaced longitudinally aligned work stations 20,only certain of which are shown in the drawings. Some of the workstations contain no tooling and thus are referred to as idle stations,while at others tools and actuating means are provided to performvarious fin removal operations on the cylinder head castings. In thepresent machine, seven active work stations are actually utilized.However, for simplicity the drawings show only two of these: one havinga valve seat definning mechanism 22 and another having an end definningmechanism 24.

Movement of the cylinder heads from station to station along the guiderails and through the machine is accomplished by means of a transfermechanism generally indicated by numeral 26. The transfer mechanismcomprises a transfer bar 28 which extends longitudinally substantiallythe length of the frame 12 and is reciprocably carried thereby onsupport rollers 30 and maintained in position by holddown rollers 32.

The transfer bar 28 carries a plurality of pivoltally mounted latchmembers 34 which are equally spaced along the lower surface thereof andare gravity actuated downwardly into positions in which they areengageable with the ends or other suitable portions of the individualcylinder head castings for moving them forward from station to stationthrough the machine (from left to right, as shown in FIGS. 1, 2, 3).Latches 34 each include a roller member 36 which, on the return strokeof the transfer bar, engages a high point of the cylinder head casting,causing the latches to lift up and ride over the castings on theirreturn to the initial position of the transfer stroke. The spacing ofthe latch members along the transfer bar is equal to the distancebetween the individual work stations.

Reciprocation of the transfer bar in a harmonic motion is provided by acrank 38 counterweighted as at 40 and connected through a link 42 andconnector member 44 with the transfer bar 28. The crank throw is sizedto provide a transfer bar stroke, or movement, of just slightly greaterthan the work station spacing to assure engagement of the latches withthe castings at the beginning of each transfer stroke. The crank 38 andconnecting link 42 are arranged to be parallel with the transfer bar 28at the ends of its stroke so that a true harmonic reciprocating motionis provided. A harmonic drive has the advantage that even though a fasttransfer speed is utilized, the rate of travel of the transfer bar willbe very slow towards the beginning and ending of each stroke. In thisway, the shock load, upon engagement of the latches with the cylinderhead castings, is reduced and, even more important, the rate of movementof the individual cylinder heads is slowed at the end of each stroke sothat no over-travel occurs. Thus, the gravity latches 34 are sufficientin themselves to properly position the cylinder head castings at eachstation and no special stopping or locating devices are required.

Drive of the crank 38 for the transfer mechanism is provided in thisinstance from the tail shaft 46 of an associated grinding machine 48,which is directly fed by the definning machine of this invention. Thearrangement is such that the cylinder head castings are transferred fromthe definning machine directly onto the table 50 of the grinder, wherethey are picked up and moved through the grinder by the lugs 5 2 of thegrinders transfer mechanism. The grinder tail shaft 46 is connected by achain 54 with crank 38 so as to drive the harmonic transfer mechanism ofthe definning machine while at the same time maintaining the transfermechanism in proper timing with that of the grinder 48. A cam 56attached on the shaft of crank 38 (as shown in FIG. 2) is arranged tointermittently engage a pneumatic pilot valve 58 for controlling theoperation of the various tools of the definning machine in a manner tobe subsequently described.

Referring now to FIG. 4 of the drawings, there is shown a cylinder headcasting 60 of the type adapted to be defined by the machine of thisinvention. In the form shown in the figure, casting 60 includes castingfins 62 extending from the opposite ends thereof, as well as additionalcasting fins 64 extending interiorally of the valve seats. Additionalfins, not shown, may also be disposed on various other surfaces of thecasting. The definning machine of this invention acts through varioustrimming and punching tools to remove excessive portions of the cylinderhead casting fins in preparation for passing of the cylinder headcasting through the grinding machine 48, where the fins are furtherreduced to a predetermined dimension suitable for final machining of thecylinder head.

FIG. of the drawings illustrates in detail one of the work sections ofthe definning machine whereby the mechanism 22 for removing fins fromcertain of the cylinder head valve seats is located. This mechanismincludes a plurality of punches 66 carried in a tool holder 68 which ismounted between a pair of support arms 70. Arms 70 are pivotallysupported at 72 on the frame 12 and are attached through a connectingmember 74 with the piston rod 76 of a pneumatic cylinder 78. Movement ofthe piston rod 76 into and out of cylinder 78 causes the pivotalmovement of arms 70 and the consequent movement of punches 66 into andout of the respective valve seat openings of a cylinder head properlylocated in the station. Suitable stop means 80 are fixed to the machineframe 12 and arranged to oppose an upper surface of the cylinder headsbeing acted upon so as to prevent upward movement of the heads duringthe punching operation.

FIG. 6 of the drawings illustrates the end definning mechanism 24 foundat another of the machine work stations. This mechanism comprises aplurality of cutoff tools 82 which are carried on arms 84 pivotallymounted on the machine frame 12. Arms 84 are, in turn, connected withthe piston rod 86 of another pneumatic cylinder 88, actuation of whichmoves the pivot arms so as to pass the cutoff tools across the end facesof any cylinder head in the station to thereby cut or break off the finsat the ends thereof. Stop means 90, which are similar to the stop means80 of the previously described station, are provided to prevent movementof the cylinder head during the cutting operation.

Referring now to FIG. 7 of the drawings, there is shown a schematicdiagram of the control and tool actuating mechanism for the machine ofthe present invention. Pressurized air from the factory source isprovided through a filter 92, pressure regulator 94 and lubricator 96 toa line 98, which feeds a plurality of spring returned pneumatic spoolvalves 100 106, plus the pneumatic pilot valve 58. Valve 58 controls thefeed of air through line 108 to the actuator 110 for spool valve 106.Valve 106, in turn, controls the feed of air to line 112, which feedsthe actuators 113 118 of spool valves 100 105, respectively. Each of thelatter spool valves controls the feed of air to and from its respectiveone of the pneumatic cylinders 78, 88 and 1 l9 122.

Spool valves 78, 88 and 1 l9 122 are connected with their respectivepneumatic cylinders by actuating lines 124 and return lines 126. Each ofthe actuating lines 124 includes a variable orifice 128 bypassed by acheck valve 130 having free flow in a direction toward the cylinder.Return lines 126 each also includes a variable orifice 132 bypassed by acheck valve 134, also having free flow in the direction of the cylinder.

In operation, rotation of the grinder tail shaft drives crank 38 throughchain 54, which causes the harmonic reciprocation of the transfer bar28. Upon forward movement of the transfer bar (from right to left inFIGS. 1 3) the various gravity latches 34 engage cylinder head castingsat the respective stations and move them to their proper positions atthe next stations. Upon the return stroke, the gravity latches arelifted up by rollers 36 and ride over the cylinder head castings, whichremain in their stations until the next forward stroke of the transferbar.

During the transfer bar return stroke, cam 56 actuates pilot valve 58 topermit a flow of air therethrough from line 98 to the actuator 110 forspool valve 106. This actuates the spool valve, permitting air flow fromline 98 through line 112 to actuators 113 118 of the various spoolvalves 105. Actuation of these valves feeds air through lines 124 to theactuating sides of the pneumatic cylinders 78, 88 and 119 122, causingthe cylinders to actuate the various definning tool mechanisms at theirvarious work stations.

After a predetermined movement of the transfer mechanism on the returnstroke, cam 56 moves away from pilot valve 58, causing it to be returnedto its inactive position. This cuts off air flow to actuator 110 andpermits spool valve 106 to close, in turn cutting off air flow toactuators 113 1 l8. Spool valves 100 then return to their initialpositions, causing air pressure to be introduced to the return sides ofthe pneumatic cylinders through lines 126 and to be exhausted from theactuating sides through lines 124 as controlled by variable orifices128. The timing of the actuation and return strokes is arranged suchthat the cylinders are completely returned to their initial positions bythe time the transfer mechanism reaches the end of its return stroke. Inthis way, the next forward movement of the transfer mechanism will movethe cylinder head castings to the next station without any interferencefrom the various defining tool mechanisms.

While this invention has been described by reference to a specificembodiment, it is not intended that the inventive concept should belimited thereby but that it should be given its full scope as defined inthe following claims.

I claim:

1. A multi-station machine for automatically sequentially performing aseries of separate operations on any number of individual parts, saidmachine comprising a main frame defining a plurality of aligned equallyspaced stations,

guide means on said frame for supporting a plurality of work pieces andarranged to guide such work pieces linearly along said frame in andbetween said stations,

mechanical transfer means including a crank mechanism, a transfer bardisposed above and extending longitudinally for substantially the lengthof said guide means and connected with said crank mechanism so as to bereciprocably driven thereby with a motion at least approaching harmonicmotion, a plurality of work piece engaging latches pivotally carried onsaid transfer bar, said latches being gravity actuated to engage suchwork pieces for movement in one direction along said guide means andpivoting to a non-engaging position during each return movement tosequentially advance such work pieces from station to station along saidguide means,

a plurality of operating means including pneumatic cylinders located atvarious of said stations, said operating means being adapted to performa plurality of different mechanical operations on said work pieces, eachsaid operating means performing a different one of such operations atits respective station, and

control means connected with said operating means to control theoperation thereof, said control means comprising a cam mechanicallyconnected with said mechanical transfer means and a pilot valveconnected to control the supply of air to said pneumatic cylinders, saidcam being arranged to actuate said pilot valve in timed relation to thestroke of said transfer bar such that the various operating means aresimultaneously actuated to perform their respective operations duringthe return movement of said transfer means and said operating means arenot in operation during the movement of such work pieces from station tostation.

2. In a multi-station machine for automatically removing fins from aseries of individual castings,

a main frame defining a plurality of longitudinally aligned equallyspaced work stations,

guide rails extending longitudinally on said frame for supporting aplurality of individual castings thereon and guiding said castingslinearly along said frame in and between said work stations,

mechanical transfer means including a continuously rotatable crankmechanism, a transfer bar reciprocably carried on rollers above saidguide means and extending longitudinally for substantially the totallength thereof, said transfer bar being connected with said crankmechanism so as to be driven thereby with a continuous harmonic motion,reciprocating through a stroke no less than the spacing of adjacent workstations, a plurality of latches pivotably carried beneath said transferbar spaced equally therealong at distances equal to the spacing ofadjacent work stations, said latches being downwardly movable by gravityinto casting engaging positions for engagement with and movement of saidcastings from one station to the next during forward travel of saidtransfer bar and said latches being pivotable out of said castingengaging positions and adapted to ride over said castings without movingthem upon the return movement of said transfer bar, such actions causingsaid castings to be sequentially advanced from station to station alongsaid guide rails,

aplurality of definning tools located at various ones of said workstations and each connected with fluid actuating means by which saidtools are operated to sequentially act upon each of said casting at thevarious work stations to cut excess fins from various locations thereonand fluid control means connected with said fluid actuating means tocontrol the operation thereof, said fluid control means beingmechanically interconnected with said mechanical transfer means suchthat said fluid actuating means are controlled to simultaneously actuatesaid definning tools to perform their respective operations during thereturn movement of said transfer bar and to avoid actuation of saidtools during the forward travel of said transfer bar.

2 33 Q UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3, 670,402 Dated June 20, 1972 Chauncey L. Dirks It is certified thaterror appears in the above-identified patent and that saidLetters-'Patent are hereby corrected as shown below:

In the Abstract, Line 1, "defining" should read --definning--. 7

Col. 1, Line 51, "defining" should read --definning-.

Col. 3, Line 5, "defined" should read --definned-x Line 18, "sections"should read --stations--: Line 18, "whereby" should read --wherein--:Line 36, "on", second occurrence, should read ----to'----.

C01. 4, Line 26, "defining" should read --defirming-.

Signed and sealed this 9th day of January 1973.

(SEAL) Attest:

ROBERT GOTTSC HALK Commissioner of Patents EDWARD M.FLETCHER,JR;Attesting Officer

1. A multi-station machine for automatically sequentially performing aseries of separate operations on any number of individual parts, saidmachine comprising a main frame defining a plurality of aligned equallyspaced stations, guide means on said frame for supporting a plurality ofwork pieces and arranged to guide such work pieces linearly along saidframe in and between said stations, mechanical transfer means includinga crank mechanism, a transfer bar disposed above and extendinglongitudinally for substantially the length of said guide means andconnected with said crank mechanism so as to be reciprocably driventhereby with a motion at least approaching harmonic motion, a plUralityof work piece engaging latches pivotally carried on said transfer bar,said latches being gravity actuated to engage such work pieces formovement in one direction along said guide means and pivoting to anon-engaging position during each return movement to sequentiallyadvance such work pieces from station to station along said guide means,a plurality of operating means including pneumatic cylinders located atvarious of said stations, said operating means being adapted to performa plurality of different mechanical operations on said work pieces, eachsaid operating means performing a different one of such operations atits respective station, and control means connected with said operatingmeans to control the operation thereof, said control means comprising acam mechanically connected with said mechanical transfer means and apilot valve connected to control the supply of air to said pneumaticcylinders, said cam being arranged to actuate said pilot valve in timedrelation to the stroke of said transfer bar such that the variousoperating means are simultaneously actuated to perform their respectiveoperations during the return movement of said transfer means and saidoperating means are not in operation during the movement of such workpieces from station to station.
 2. In a multi-station machine forautomatically removing fins from a series of individual castings, a mainframe defining a plurality of longitudinally aligned equally spaced workstations, guide rails extending longitudinally on said frame forsupporting a plurality of individual castings thereon and guiding saidcastings linearly along said frame in and between said work stations,mechanical transfer means including a continuously rotatable crankmechanism, a transfer bar reciprocably carried on rollers above saidguide means and extending longitudinally for substantially the totallength thereof, said transfer bar being connected with said crankmechanism so as to be driven thereby with a continuous harmonic motion,reciprocating through a stroke no less than the spacing of adjacent workstations, a plurality of latches pivotably carried beneath said transferbar spaced equally therealong at distances equal to the spacing ofadjacent work stations, said latches being downwardly movable by gravityinto casting engaging positions for engagement with and movement of saidcastings from one station to the next during forward travel of saidtransfer bar and said latches being pivotable out of said castingengaging positions and adapted to ride over said castings without movingthem upon the return movement of said transfer bar, such actions causingsaid castings to be sequentially advanced from station to station alongsaid guide rails, a plurality of definning tools located at various onesof said work stations and each connected with fluid actuating means bywhich said tools are operated to sequentially act upon each of saidcasting at the various work stations to cut excess fins from variouslocations thereon and fluid control means connected with said fluidactuating means to control the operation thereof, said fluid controlmeans being mechanically interconnected with said mechanical transfermeans such that said fluid actuating means are controlled tosimultaneously actuate said definning tools to perform their respectiveoperations during the return movement of said transfer bar and to avoidactuation of said tools during the forward travel of said transfer bar.